Apparatus for separating gases from liquids



May 22, 1945.

L. MCCULLOCH APPARATUS FORSEPARATING GASES FROM LIQUIDS Filed Deo. s,y1942 /'g/ J// En INVENTOR WITNESSES:

y Patented May 22, 179.45

UNITED- STATES PATENT `olf-'F1os FROM LI QUIDS Leon Mecmloth, Pittsburghc, Pa., assignmte Westinghouse Electric & Manufacturing Company, EastPittsburgh, Pa., a corporation'oi Pennsylvania l Application December 3,1942, Serial No. 467,756

2 claims.

This invention relates to 'apparatus for separating gases from liquids,in particular oils and other liquids tending to excessive foaming whensubjected to reduced pressures.

This invention relates to apparatus for subiecting liquids, particularlyoil, to reduced pressures in order to separate therefrom absorbed,dissolved or entrained gases. For many reasons, the most economical andpractical method of separating gases dissolved or absorbed in liquids isto subject thevliquid to evacuation. Under these conditions, theIquantity of gas which can be held in solution will be reduced, since.the partial pressure of the gas determines roughly the quantity thatmay be held in solution. Unfortunately, liquids having certainsurface-proper.- l

(Cl. 18S-2.5)

For a fuller understanding of the nature and objects of this invention,reference should be had to the accompanying drawing, in which:l

Figure 1 is a vertical cross-section of one form 5 of the invention; and1 Fig. 2 is arvertical cross-section of another form of the invention.

Referring to Figure 1 of the drawing, there is illustrated ltheapparatus I for treating a liq- 1o uid, such as oil, to remove any gasesdissolved,

absorbed vor entrained therein, as well as low boiling point liquidswhich may be removed by evacuation. Th apparatus II) comprises anenclosed receiver I having an upper wall I4 and i5 a bottom wall I6. Forsmall installations, the

receiver I2 may be made o1' a transparent material, such as a largediameter glass tube, or the like. Inthecase of apparatus suitable fortreati ing large quantities of oil, the receiver I2 may be made 'ofsteel or other suitable metal. 'I'he uid being treated. Fixed to theends of theconduits I8 are spray or atomizing heads 20 for.

foam in order to separate the liquid from the v gases is accomplished bypracticing the invention disclosed herein. v i The inventionisparticularly eiective in separating gases from dielectric liquids,such as oil and halogenated hydrocarbons. In order to maintainpredetermined dielectric properties,

these liquid dielectrics must be relatively free' from gasesand'dispersions oi" moisture.

, construction should be capable of withstanding a high vacuum. Passingthrough the upper wall I4 of the receiver I2 are located one or moreconduits I8 for introducing the oil or other liqdistributing the 'oilvina nnely divided state 22 for most etcient operation.

Intermediate the endwalls Il and I6 of the I reservoir is locatedabarrier or partition 2l substantially separating the upper portion .ofthe receiver from the lower portion. Disposed on the I ,barrier orpartition 24 Within the upper portion of the receiver to within a shortdistance of the spray heads 2li is a illling or packing character- .1nlubricating thebearings and seals of hydrogen cooled generators, it hasbeen found-that the lubricatingV oil will pick up a mix-ture of bothhydrogenanri oxygen. Since the common prac-'- tice is to circulate thelubricating oils to the bearings and seals, it is advisable to removeboth the hydrogen and oxygen gases from the lubrieating oil beforereturning the oil to the bearings. There are numerous other applicationsin which the separation of gases from oils is beneflcial. This inventionlends itself to eiectively treating the oils to separate any gasespresent therein.

The object of this invention is to provide for o treating liquids vtoseparate gases therein by means of reduced pressures without excessivefoaming. Y

@ther objects of the invention will in part be obvious and will in partappear hereinafter.

ized by a greatly extended surface with tortuous passagewaystherethrough.v The :Illlingv 26 may consist of beads or porcelainsaddles of the type employed in chemical towers or, in some cases,brickwork, or porcelain or ceramic bodies of 'numerous shapes. Thefilling 26 is so arranged that foam produced by the oil spray 22 isdepOSited on the lling whereby the foam and oil may be drawn through thetortuous passageways in the)4 filling 26.

The barrier or partition 24 is provided with an open ended tube 28 ofrelatively small crosssectional area whereby restricted communicationyis afforded` between the upper portion of the receiver and thelowerportion. The open upper end of tube 28v is located just above thespray 22. For areservoir I2 of a diameter of I4 inches,l

`the tube 28may be from one to three'inches in diameter.`

'openings 3Ii-justl above the barrier 2l in' com- The tubel 2s isprovided with@l p1ura1ity. ofy

munication with the-lling 25. Oil aiid gases penetrating Athe filling 26will escape through the" bpenings stand run down the tube 2s into thelower portion of the reservoir. The lower end ofthe tube is preferablytted with a coarse screen- 132. In the specic example' given, thisscreen mayconsist of holes of from one-eighth inch to one-quart'erinchin diameter.

The lower portion ofthe receiver |2'is provided with an'evacuating'conduit 34 connected to a Qvacuu'm pump. Gases are withdrawn through theconduit 34 under the action of the vacuum pump .and a predeterminedreduced pressure is maina,"s7a,vo4r. f e

minute, have been treated, with successful and satisfactory resultsbeing obtained.`

In some cases, a modified form of construction has been found tobeoperative as illustrated in Fig. 2 of the drawing; In this constructionuthe l apparatus 40 comprises a receiver-'42 having a tained in the lowerportion of the receiver. Oil

dripping from the upper portion of the receiver through the conduit 26forms a pool 36 on the.

bottom wall I6 of the reservoir, from which the ioilenay be removed bythe gear pumpy 36 as detsir i l The apparatus is so arranged that adifferential pressure is maintained by means 'of the restricted ,1 areatube Zl'between the lower portionof the `reservoir iontc which thevacuum conduit 34 ex- ;tendsand the upper portion into which the oil llis sprayed. .For many purposes, a differential 1 pressure of 2 to 1 0millimeters of mercury between these portions of the reservoir issufllcient tocarry gforward av highly eicient separation of gases 1 fromthe oil. It has been found necessary that the evacuating conduit means34 be located at a point-within the lower portion of the reservoir. Thedifferential gas pressure between the upper g and lower portions and theweight of the spray and any roam produced exert a driving force tend- Iing to pushthe sprayed oil-.and foam through the nlling 26. 'Theextended surface of the-lling 26 and the tortuous passages have beenfound to be highly effective in breaking'up the foam and ex- 1 posing alarge surface of the oil to the reduced pressure. Gases and water arereadily-vaporized and separated from the oil under these conditions.

` As the oil collects above the baille 14,' itwill seep through theopenings 30 and trickle down into the lower portion of the receiver.

As the oil is sprayed at 52, it will be found that a lfoam is producedalmost instantaneously. The y, foam may beseveral inches deep. As arule, 'the colder the oil the greater the thickness of the foam. Forexample, at 32 C. in the seti-up above disclosed, the foam wasfourinches high, while an'd gases are -withdrawn 1 the openings 30 andthe conduit'26, and flow into 1' the lower portion of sizeable pool ofoil 36 at the at timeshave 1a iight surface layer of foam, but l thiscondition is not harmful. IIn the apparatus i mentioned. from one to theopen end of -However a substantial portion of the gasisenresultingeffective separarespectively through the receiver .without any amount offoam running through. The bottom of the receiver may two gallons of oilper immediately, and

lower closure 46 and an upper closure 44 through which the oil conduits48 extend. The spray heads 60 distribute the oil in the form of a foamyspray 52 upon a series of baliles 54, 56. The baiiles 54, 56 arearranged in staggered relation, whereby a tortuous passage 65, 51 isproduced, forcing the oily foam to pass over large surface areas of thebailles. While only a few bailles have been shown, it is desirable toemploy a great number thereof arranged in various formations, in somecases including punched holes in staggered relation, to providea largesurface area of contact with the foam. The partition 56 is disposed beflo'w the bailles V54, 56 and divides the receiver into two portions.Communication between the upper portion of the receiver and the lowerportion of the receiver as defined by the partition 58 is esa tablishedthrough the restricted conduit 60, open at the upper end and closedwith-a coarse screen 64 at the lower end. 'I'he openings r62 function topermit the`trick1ing of oil and separatedgases portion to -the lowerportion'of from the baille The -conduit is connected to the receiver 42.

a 'source of vacuum, such as arvacuum pump', and

' withdraws gases from the l'receiver under a predetermined vreducedpressure. Oil separated from the gases forms a pool I0 at the bottom ofth'e reservoir and is removed by means of the gear pump 68'.Y e

It will be appreciated that in both forms of the invention, the foamproduced by the'spraying of the oil containing gases therein issubjectedto a driving forcewhich-bauses the foam to be drawn over a large;surface area and through tortuous passages, thereby causing the oil'andgas to separate. It has lbeen found not suflicient to simply spray'the/oil against baies or other filling unless a force preferably a. gaspressure is exerted to cause all of the foam to pass regularly over thisextended surface.

The device shown in the drawing has been found 'to function successfullywith wet, cold oils from the scope thereof, it is i trapped within'thefoam resting onthe nlling 26. L This foam is forced through the packing26 by the dierential pressure and gravity, in its being broken up withan i tion of the'gases from the oil.

The separated oil l which customary types of equipment have been -ioundto be unable to handlev without excessive foaming.

It will be obvious to .those skilled in the art that manyrnodiiicationsin the type-of filling and its arrangement may be effectedvwithoutchanging the gist of the invention.

' Since certain obvious vchanges may be made in the above procedure anddifferent embodiments of the invention 'could be madev without departingmatter contained in the above descriptiovshould be considered asillustrative and not in a limiting l sense.

I claim as my invention: .1. Anapparatus for separ ting gases fromoiland other liquids normally tending. to foam yexcessively whensubjectedto evacuation, compris- 'ing an `enclosed receiver, means fordistributing the oil in a inely divided state disposed at the upper' endIof the receiver, a vpartition extending across the receiver disposedintermediate the upper and lowerends of therec'eiver `to close-offsubstantially the' entire', cross-sectional area of.

a restricted passagemember passing the receiver,

and extending to a position through the partition adjacent the oildistributing means and labove the.

intended that all member having openings adjacent the portion of fillingimmediately `above the partition, the openings providing for flow of oiland gas into the restricted passage member and to the portion of thereceiver below the partition, means for withdrawing gases under reducedpressure disposed in the receiver below the partition, the reducedpres-v sure so produced being effective on the oil through therestricted passage. and means for withdrawing oil from the portion ofthe receiver below the partition. the apparatus being so arranged that adiierence in pressure exists between the zone above the iilling and theportion below the partition whereby any oil or foam impinging on thelling is forced throughthe tortuous passages of the filling over theextended surface and through the openings into the lower portion of theref ceiver, the' foam thus being broken up into gas liquids, theapparatus being capable of effecting such separation without theapplication of heat to the liquid, comprising, a tank, means forsupliquid within thejtank, a body comprising a plurality of members ofextended surface area and relatively irregular passages therebetweendisposed acrosssubstantially the entire cross-sec tional area -of thetank below said atomizing means, a restricted passage member through thebody for withdrawing gases separated from the liquid on atomization, therestricted passage member having openings adjacent the end of the bodyremote from' the atomizing means, the openings being located to allowliquid to flow therethrough into the passage of the member, theatomized' liquid being deposited upon the body, means for withdrawingthe gases at a reduced pressure operatively connected to the tank at aposition below the body. the atomized liquid being forced over thesurface area of the members of the body and through the irregularpassages by the diierence in pressure createdby the reduced pressuremeans, foam formed -being forced through the body and accordingly beingbroken down into gas and liquid, the restricted passage member and theopenings therein providing the sole means for withdrawing the liquid andgases into the portion of the tank below the body,

'LEON Mcurimcn.

